Assembly jig for miniature electrostatically deflected cathode ray tubes

ABSTRACT

A jig holds the electrodes of a miniature electrostatically deflected cathode ray tube in place while receiving molten glass rods to affix the electrodes in position. The jig holds the electrode parts with the tube axis horizontal in a series of slots and contoured receptacle chambers which are manually loaded and held in place by gravity until the jig is fully loaded. Separate pressure pad clamping arrangements are then positioned to bear both vertically and axially on the electrode parts to hold them precisely in position for receiving molten glass rods.

United States Patent Blumenberg et all.

[451 Oct. 10,1972

[ ASSEMBLY MG FOR MINEATURE ELECTROSTATICALLY DEFLECTED CATHODE RAY TUBES [72] Inventors: Horst H. Blumenberg, Owensboro; Francis W. Francillon, Maceo, both of Ky.

[73] Assignee: Kentucky Electronics Inc., Owensboro, Ky.

[22] Filed: Dec. 22, 1970 21 Appl. No.: 100,624

[52] US. Cl ..29/203 .1, 29/283, 269/40, 269/44, 269/254 R, 269/321 W [51] Int. Cl. ..B23q 3/18, B23p 17/04, B25b H20 [58] Field of Search ..269/9, 10, 43, 44, 40, 254 R, 269/321 T, 321 W; 29/203 .1, 203 P, 283

[56] References Cited UNITED STATES PATENTS 1,048,821 12/1912 Gill ..269/43 X 1,396,162 11/1921 Campbell ..269/40 X 1,432,926 10/ l 922 Thomsen ..269/43 2,316,355 4/1943 Nesbit ..269/40 X 2,706,232 4/ 1955 Pilas ..269/40 X 2,919,128 12/1959 Blattel ..269/40 2,954,972 10/ 1 960 Collins ..269/44 3,068,825 12/ 1962 Knauf ..269/40 3,264,721 8/ 1966 Fitzpatrick ..29/ 200 J 1,456,506 5/1923 Leveridge ..269/321 W 2,721,374 10/1955 Pilas ..269/321 W Primary ExaminerWayne A. Morse, Jr.

Attorney-Laurence R. Brown [57] ABSTRACT A jig holds the electrodes of a miniature electrostatically deflected cathode ray tube in place while receiving molten glass rods to affix the electrodes in position. The jig holds the electrode parts with the tube axis horizontal in a series of slots and contoured receptacle chambers which are manually loaded and held in place by gravity until the jig is fully loaded Separate pressure pad clamping arrangements are then positioned to bear both vertically and axially on the electrode parts to hold them precisely in position for receiving molten glass rods.

8 Claims, 1 1 Drawing Figures P'A'IENTEMBI' 10 Ian FIGZ SHEEI 1 0F 4 FIG! INVENTORS FRANCIS W FRANCILLON' HORST H. BLUMENBERG BY MQM ATTORNEY PATENTEBBBI 10 I972 INVENTORS FRANCIS W FRANCILLON HORST H. BLUMENBERG BY QDM ATTORNEY PHENEFEWF 1 0 w 3,695.49 1

SHEEK & flF Q INVENTORS FRANCIS W. FRANCILLON HORST H. BLUMENBERG mfg 52am ATTORNEY ASSEMBLY JIG FOR MINIATURE ELECTROSTATICALLY DEFLECTED CATHODE RAY TUBES This invention relates to the assembly and manufacture of cathode ray tubes and more particularly it relates to assembly jigs for spacing and orienting cathode ray tube electrodes precisely in place in an electron gun assembly during manufacture.

In cathode ray tubes the characteristics from tube to tube may change by very small variations in the spacing and orientation of the electrodes. This is particularly true in the case of miniature tubes which have an electrostatically deflected beam. It is always desirable to establish uniform characteristics in tubes being manufactured and this is particularly critical in miniature tubes used as indicia or character generating tubes. Side-by-side indicia tubes should display characters of identical shape and orientation in response to similar character generation signals, and small variations of electrode spacing or orientation prevent uniformity.

Because of the closely spaced electrodes and the resulting critical electric field configuration within the electron gun in a miniature tube, usual positioning tolerances for larger tubes are no longer acceptable, and the assembly tolerances of the electrodes becomes critical. Also the miniature tubes have smaller electrodes and closer spacing which physically causes difficulty in assemblyof electron guns, particularly when the electrodes are hand loaded in a jig assembly. Conventional assembly jigs are not adapted for simplified manual loading of very small parts. Complex loading sequences or the necessity for dependency upon an assembler to establish the spacing or orientation of the electrodes should be avoided. Also the necessity for an operator to work in very small spaces requires special attention to the accessibility of the assembly jig. Some assembly jigs are made to custom build special tube types. This requires expensive and largely duplicated equipment for manufacturing a variety of tube types.

Prior art assembly jigs have not been found satisfactory to solve these problems.

Accordingly it is an object of this invention to provide improved assembly jigs.

Another object of the invention is to provide a jig assembly affording accessible manual loading of electrode parts for miniature cathode ray tubes.

A further object of the invention is to provide a versatile jig assembly for holding electron gun parts in critically spaced and oriented positions yet adaptable to handle various electron gun configurations.

In accordance with this invention therefore a modularized jig assembly is provided for holding electron gun parts individually in appropriately formed receptacles. The electron gun is aligned with its axis horizontally oriented during loading of electrodes into a corresponding receptacle portion of the jig assembly. Spring loaded axial clamping members are provided at both ends to position the terminal electrodes. A removable spring loaded top clamping assembly is affixed to the receptacle portion to firmly hold the electrodes in place when receiving a molten glass rod. The entire jig assembly is then adapted to be loaded into a beading machine that affixes molten glass rods onto the electrodes or their mounting brackets thereby holding in the electrode assembly the electrodes in critical permanently spaced and oriented position.

Further objects, features andadvantages of the invention will be found throughout the following detailed description, which refers to a preferred embodiment illustrated in the accompanying drawing, wherein:

FIG. 1 is a partial view of a beading machine for permanently fixing electrodes in place with molten glass rods.

FIG. 2 is a broken-away view, partlyin section of a miniature electrostatically deflected cathode ray tube assembly which can be assembled by means of the jig assembly provided by this invention.

FIG. 3 is a side elevation view of an assembly jig embodiment afforded by this invention.

FIGS. 4 through 8 illustrate various modules of the assembly jig as used for electrodes of different configuration.

FIG. 9 is a perspective view of a grid locater block assembly.

FIG. 10 is a nest assembly elevation view for locating grids.

FIG. 11 is a plan view of a flat grid with locating indents.

Referring now to FIG. 1, there is shown a portion of a beading machine with two pivot arms 10, 11 which hold corresponding glass rods 12, 13 with molten faces, by means of air suction through the inner pipe structure 14, in diametrically opposed positions for impaling upon the electrode assembly l5 of a cathode ray tube.

A typical electrode assembly for a miniature electrostatically deflected cathode ray tube with electrodes held in place by glass rods l6, 17 is shown in FIG. 2. Such tubes may be constructed with various flat apertured plates 18, 19, 20, 21, 22 intermixed with some cylindrical electrodes 23, 24 and deflection assemblies 25, 26 all aligned along the axis 27 of the tube. As may be seen, the plate electrodes have diametrically opposed extremities embedded in the glass rods l6, 17 while the cylindrical electrodes 23, 24 and one set of deflection plates 25 may have mounting brackets 28, 29, 30 extending therefrom to'be embedded into the glass rods 16, 17. It may be seen from the orientation of the electrodes that they may be held in place during the entry of the glass rods by an assembly jig grasping the electrodes below and above the plane. of the drawing of FIG. 2.

Such a jig is constructed for registration in a fixed position in the block 31 of the beading machine of FIG. 1 to expose the mounting brackets 28, 29, 30 and ends of the plate electrodes 18, 19 etc., at opposite sides to receive the molten rods 12, 13 without removal of the parts from the assembly jig until the rods are frozen in place to permanently hold the electrodes in proper of pivot arms 37, 38 which engage slots in the receptacle frame posts 39, 40. The top view of the clamp plate 35 may be seen in FIG. 4 together with the slotted configuration 41 which aligns the various modular spring loaded pad sections 42, 43, etc. It is seen that a series of different spring loaded pad modules can be selected for spacing and positioning to adapt to a variety of different electron gun configurations within the same general tube size. A typical size tube for which this assembly jig is adapted is of outer diameter less than three-fourths of an inch and length of less than 3 inches. As can be seen each spring loaded pad has a length and axial position such that it engages and holds in place an electrode against a lower modular receptacle 44, 45, 46, 47, etc. Thus, pad assembly 42 holds the cathode cylinder 23 in place within modular receptacle 44 and pad assembly 43 holds the deflection electrode plate 26 in place against the center pin 48 of the axial clamp assembly 49.

Bolts 50 hold the various receptacle assemblies in place axially. Shims or spaces between the modules prevent changes in critical spacing. The construction of these receptacle assemblies may be seen in FIGS. to 8. Thus the receptacle 44 (or 51) is adapted to receive seated in a V-shaped crotch a cylindrical electrode such as cathode 23 or grid cylinder 24. Terminal cathode cylinder 23 is axially positioned by post member 52 of the axial clamp assembly 53 when aligned against stop 54. The axial clamp assemblies 49, 53 may be removed to a retracted position by twisting and releasing by means of a key-slot structure 55, 56 when electrodes are being loaded in the receptacle frame assembly 32 with top clamp 35 removed.

At each end of'the receptacle 5] for grid cylinder 24 are spacer plates 57, 58, which are oriented with slot plates 59 such as shown in FIG. 7 to receive the plate electrodes 18, 19, 20, 21 and 22 in proper position in slots 60 etc., formed by an indentation in the plates 59.

Two deflection electrodes 25 are held side by side in slots 61, 62 by receptacle 46 as shown in FIG. 8, and appropriate padded spring assemblies 63 are aligned to contact and hold down each deflection plate separately.

Deflection electrode plates 26 are held in place by receptacle structure 47 as shown in FIG. 6 by aid of the pin structure 48 of end clamp 49 which holds the lower plate 26 down and serves as the receptacle for the upper plate 26 which in turn is held down by spring pad assembly 43.

In use therefore to prepare for loading, the end clamp assembly 49, 53 at each end will be removed to retracted position, and the upper clamp assembly 35 will be removed. Then all the electrodes with the exception of the upper deflection plate 26 will be placed in their receptacle position where they lie by force of gravity. Thereafter the end spring clamp assemblies 49, 53 are positioned in their clamping position as shown in FIG. 3. Then the upper deflection plate 26 is placed upon the shaped pin receptacle assembly 48 and the upper clamp assembly 35 is positioned and tightened in place by pivot clamp members 37, 38. The entire assembly jig then holds all electrodes with diametrically opposing sides free and brackets 28, 29, etc., and elec' trode ends extending. Then the assembly jig is placed in a beading assembly such as shown in FIG. 1 in a registered position to receive the molten glass rods. The

' electron assembly is removed from the assembly jig after the glass rods are frozen in place and the jig is removed from the beading machine by removing the upper clamp 35 and retracting the end clamp assemblies 49, 53 and lifting out the finished electrode assembly such as shown in FIG. 2.

Each electrode is confined laterally by structure included by the shaping of the receptacle such as the crotch of receptacle 44 or the slots of receptacle 46 or by externally positioned end stops 70, 71 for the deflection plates 26, etc.

The spring pad assemblies may comprise spring loaded pin extensions as in assembly 43, or may comprise a leaf spring clamp member 73 which has an additional spring loaded pad member 42 aiding the vertical spring pressure downward onto cylindrical electrode 23.

Grids may be located within the tube structure by a module assembly such as shown in FIG. 9. On each side phase 91 of this module would be located a grid nesting assembly 92 as shown in FIG. 10. Two slots 93, 94 are provided for receiving grids 95 as shown in FIG. 11, having notched locating indents 96, 97. In looking at the elevation view of FIG. 10 therefore there would be 2 pins 98 inserted therethrough for registration with the indents 96, 97 of the flat grid end 95.

In operation, when the grid is stamped from a single die with aperture 99 located precisely with respect to indents 96, 97, this assembly precisely aligns the electron gun axls.

What is claimed is:

1. An assembly jig for holding a plurality of diversely shaped electrodes of a cathode ray tube in exact spaced positions and orientated along a common axis with two opposed portions of the electrodes thereof extended with members for receiving thereon molten glass rods to permanently hold the electrodes in position, com prising in combination, a receptacle frame including a plurality of receptacles shaped for receiving said electrodes of different shape in said positions in axial alignment along said axis in a horizontally oriented array to receive the electrodes and hold them in initial position by force of gravity with said members extending in a substantially horizontal plane, a removable clamping frame having spring loaded pads for engaging each of the electrodes to press them into said shaped receptacles and hold them in said axial alignment and means affixing said clamping frame in place adjacent to said receptacle frame so that each of said pads engages an electrode when in place with a spring bias holding it in its corresponding receptacle.

2. An assembly jig as defined in claim 1 wherein the plurality of receptacles are individual modularized sections removably held in place in said receptacle frame.

3. An assembly jig as defined in claim 1 having a retractable end clamp assembly for holding at least one end electrode in axial position in a corresponding one of said receptacles.

4. An assembly jig as defined in claim 3 having an assembly for receiving two vertically spaced deflection electrodes at one end of the electrode assembly wherein said end clamp holds in position the lower deflection electrode in one of said receptacles and has thereon structure forming a receptacle for the upper deflection electrode.

cluding a receptacle for the plate electrode which comprises a plate having an indentation on one side and a spacer plate positioned adjacent the indentation to form a slot for receiving said flat plate electrode.

8. An assembly as defined in claim 7 wherein said flat plate electrode has two locating indents on one edge, and wherein said receptacle for the plate electrode includes locater pins registering with said indents. 

1. An assembly jig for holding a plurality of diversely shaped electrodes of a cathode ray tube in exact spaced positions and orientated along a common axis with two opposed portions of the electrodes thereof extended with members for receiving thereon molten glass rods to permanently hold the electrodes in position, comprising in combination, a receptacle frame including a plurality of receptacles shaped for receiving said electrodes of different shape in said positions in axial alignment along said axis in a horizontally oriented array to receive the electrodes and hold them in initial position by force of gravity with said members extending in a substantially horizontal plane, a removable clamping frame having spring loaded pads for engaging each of the electrodes to press them into said shaped receptacles and hold them in said axial alignment and means affixing said clamping frame in place adjacent to said receptacle frame so that each of said pads engages an electrode when in place with a spring bias holding it in its corresponding receptacle.
 2. An assembly jig as defined in claim 1 wherein the plurality of receptacles are individual modularized sections removably held in place in said receptacle frame.
 3. An assembly jig as defined in claim 1 having a retractable end clamp assembly for holding at least one end electrode in axial position in a corresponding one of said receptacles.
 4. An assembly jig as defined in claim 3 having an assembly for receiving two vertically spaced deflection electrodes at one end of the electrode assembly wherein said end clamp holds in position the lower deflection electrode in one of said receptacles and has thereon structure forming a receptacle for the upper deflection electrode.
 5. An assembly as defined in claim 1 wherein at least a portion of the spring loaded pads comprise spring loaded pin extensions for engaging an electrode placed in a corresponding one of said receptacles.
 6. An assembly as defined in claim 1 having a receptacle surface for cylindrical electrodes shaped with a V-shaped crotch.
 7. An assembly as defined in claim 1 wherein the electrodes comprise at least one flat plate electrode including a receptacle for the plate electrode which comprises a plate having an indentation on one side and a spacer plate positioned adjacent the indentation to form a slot for receiving said flat plate electrode.
 8. An assembly as defined in claim 7 wherein said flat plate electrode has two locating indents on one edge, and wherein said receptacle for the plate electrode includes locater pins registering with said indents. 